oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 3 )

2018 ( 11 )

2017 ( 10 )

2016 ( 16 )

Custom range...

Search Results: 1 - 10 of 3838 matches for " Lucas Amenga-Etego "
All listed articles are free for downloading (OA Articles)
Page 1 /3838
Display every page Item
An integrative statistical model for inferring strain admixture within clinical Plasmodium falciparum isolates
John D. O'Brien,Zamin Iqbal,Lucas Amenga-Etego
Quantitative Biology , 2015,
Abstract: Since the arrival of genetic typing methods in the late 1960's, researchers have puzzled at the clinical consequence of observed strain mixtures within clinical isolates of Plasmodium falciparum. We present a new statistical model that infers the number of strains present and the amount of admixture with the local population (panmixia) using whole-genome sequence data. The model provides a rigorous statistical approach to inferring these quantities as well as the proportions of the strains within each sample. Applied to 168 samples of whole-genome sequence data from northern Ghana, the model provides significantly improvement fit over models implementing simpler approaches to mixture for a large majority (129/168) of samples. We discuss the possible uses of this model as a window into within-host selection for clinical and epidemiological studies and outline possible means for experimental validation.
Seeking consent to genetic and genomic research in a rural Ghanaian setting: A qualitative study of the MalariaGEN experience
Paulina Tindana, Susan Bull, Lucas Amenga-Etego, Jantina de Vries, Raymond Aborigo, Kwadwo Koram, Dominic Kwiatkowski, Michael Parker
BMC Medical Ethics , 2012, DOI: 10.1186/1472-6939-13-15
Abstract: The study used a rapid assessment incorporating multiple qualitative methods including in depth interviews, focus group discussions and observations of consent processes. Differences between verbal information provided during community engagement processes, and consent processes during the enrolment of cases and controls were identified, as well as the factors influencing the tailoring of such information.MalariaGEN participants and field staff seeking consent were generally satisfied with their understanding of the project and were familiar with aspects of the study relating to malaria. Some genetic aspects of the study were also well understood. Participants and staff seeking consent were less aware of the methodologies employed during genomic research and their implications, such as the breadth of data generated and the potential for future secondary research.Moreover, trust in and previous experience with the Navrongo Health Research Centre which was conducting the research influenced beliefs about the benefits of participating in the MalariaGEN study and subsequent decision-making about research participation.It is important to recognise that some aspects of complex genomic research may be of less interest to and less well understood by research participants and that such gaps in understanding may not be entirely addressed by best practice in the design and conduct of consent processes. In such circumstances consideration needs to be given to additional protections for participants that may need to be implemented in such research, and how best to provide such protections.Capacity building for research ethics committees with limited familiarity with genetic and genomic research, and appropriate engagement with communities to elicit opinions of the ethical issues arising and acceptability of downstream uses of genome wide association data are likely to be important.
Haplotype Analyses of Haemoglobin C and Haemoglobin S and the Dynamics of the Evolutionary Response to Malaria in Kassena-Nankana District of Ghana
Anita Ghansah, Kirk A. Rockett, Taane G. Clark, Michael D. Wilson, Kwadwo A. Koram, Abraham R. Oduro, Lucas Amenga-Etego, Thomas Anyorigiya, Abraham Hodgson, Paul Milligan, William O. Rogers, Dominic P. Kwiatkowski
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0034565
Abstract: Background Haemoglobin S (HbS) and C (HbC) are variants of the HBB gene which both protect against malaria. It is not clear, however, how these two alleles have evolved in the West African countries where they co-exist at high frequencies. Here we use haplotypic signatures of selection to investigate the evolutionary history of the malaria-protective alleles HbS and HbC in the Kassena-Nankana District (KND) of Ghana. Methodology/Principal Findings The haplotypic structure of HbS and HbC alleles was investigated, by genotyping 56 SNPs around the HBB locus. We found that, in the KND population, both alleles reside on extended haplotypes (approximately 1.5 Mb for HbS and 650 Kb for HbC) that are significantly less diverse than those of the ancestral HbA allele. The extended haplotypes span a recombination hotspot that is known to exist in this region of the genome Significance Our findings show strong support for recent positive selection of both the HbS and HbC alleles and provide insights into how these two alleles have both evolved in the population of northern Ghana.
Adolescents’ Willingness and Intentions to Use Contraceptives in Rural Ghana  [PDF]
Sulemana Abubakari, Yeetey A. Enuameh, Emmanuel Mahama, Obed Ernest A. Nettey, George Adjei, Gifty Fosuaa Nuamah, Edward Apraku Anane, Robert Adda, Francis Dzabeng, Seeba Amenga-Etego, Charles Zandoh, Kwaku Poku Asante, Seth Owusu-Agyei
Open Journal of Social Sciences (JSS) , 2015, DOI: 10.4236/jss.2015.311029
Abstract: Efforts made to improve the availability and access to family planning services to adolescents in Ghana have not yielded the desired results. Adolescents in the Kintampo Health and Demographic Surveillance System area are no exception. This study explored contraceptive use intentions, preferences and their determinants among adolescents in rural Ghana. This was to contribute evidence towards achieving universal access to reproductive health. A cross-sectional study design was used to collect Sexual and Reproductive Health data in the Kintampo districts in 2011. A total of 1805 female adolescents were randomly sampled from a resident female adolescent population of 16,795. This study used intention and/or willingness of adolescents to use contraceptives as the outcome variable and the explanatory variables were demographic and socioeconomic factors. Descriptive and inferential statistical analyses were done. The findings indicated 54.3% of adolescents’ were willing to use contraceptives. Injectable was the most preferred contraceptive method among adolescents (48.6%); this was followed by the pill (29.6%) with the least being foam or jelly (0.2%). The most commonly cited reason for not intending to use contraception was adolescents’ opposition to family planning (31.5%) followed by a fear of side effects (25.8%). Age and education influenced adolescents’ willingness to use contraceptives in the future. Formal education of the young generation coupled with knowledge of contraceptive methods could yield positive outcomes for contraceptive use and ultimately reproductive health of the adolescent population in the near future.
An Evaluation of the Clinical Assessments of Under-Five Febrile Children Presenting to Primary Health Facilities in Rural Ghana
Frank Baiden, Seth Owusu-Agyei, Justina Bawah, Jane Bruce, Mathilda Tivura, Rupert Delmini, Stephaney Gyaase, Seeba Amenga-Etego, Daniel Chandramohan, Jayne Webster
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0028944
Abstract: Background The shift to test-based management of malaria represents an important departure from established practice under the Integrated Management of Childhood Illnesses (IMCI). The possibility of false results of tests for malaria and co-morbidity, however, make it important that guidelines in IMCI case assessment are still followed. Methods and Findings We conducted a cross-sectional observational study to evaluate current practices in IMCI-based assessment of febrile children in 10 health centres and 5 district hospitals, with follow up of a subset of children to determine day 7–10 post-treatment clinical outcome. Clinical consultation, examination and prescribing practices were recorded using a checklist by trained non-medical observers. The facility case management of 1,983 under-five years old febrile children was observed and 593 followed up at home on days 5–10. The mean number of tasks performed from the 11 tasks expected to be done by the IMCI guidelines was 6 (SD 1.6). More than 6 tasks were performed in only 35% of children and this varied substantially between health facilities (range 3–85%). All 11 tasks were performed in only 1% of children. The most commonly performed tasks were temperature measurement (91%) and weighing (88%). Respiratory rate was checked in only 4% of children presenting with cough or difficulty in breathing. The likelihood of performing “better than average number of tasks” (>6) was higher when the consultation was done by medical assistants than doctors (O.R. = 3.16, 1.02–9.20). The number of tasks performed during assessment did not, however, influence clinical outcome (O.R. = 1.02, 0.83–1.24). Conclusion Facility-tailored interventions are needed to improve adherence to IMCI guidelines incorporating test-based management of malaria. Studies are needed to re-evaluate the continued validity of tasks defined in IMCI case assessment guidelines.
An Open Label, Randomised Trial of Artesunate+Amodiaquine, Artesunate+Chlorproguanil-Dapsone and Artemether-Lumefantrine for the Treatment of Uncomplicated Malaria
Seth Owusu-Agyei, Kwaku Poku Asante, Ruth Owusu, Martin Adjuik, Stephen Amenga-Etego, David Kwame Dosoo, John Gyapong, Brian Greenwood, Daniel Chandramohan
PLOS ONE , 2008, DOI: 10.1371/journal.pone.0002530
Abstract: Background Artesunate+amodiaquine (AS+AQ) and artemether-lumefantrine (AL) are now the most frequently recommended first line treatments for uncomplicated malaria in Africa. Artesunate+chlorproguanil-dapsone (AS+CD) was a potential alternative for treatment of uncomplicated malaria. A comparison of the efficacy and safety of these three drug combinations was necessary to make evidence based drug treatment policies. Methods Five hundred and thirty-four, glucose-6-phosphate dehydrogenase (G6PD) normal children were randomised in blocks of 15 to the AS+AQ, AL or AS+CD groups. Administration of study drugs was supervised by project staff and the children were followed up at r home on days 1,2,3,7,14 and 28 post treatment. Parasitological and clinical failures and adverse events were compared between the study groups. Main Findings In a per-protocol analysis, the parasitological and clinical failure rate at day 28 post treatment (PCF28) was lower in the AS+AQ group compared to the AL or AS+CD groups (corrected for re-infections: 6.6% vs 13.8% and 13.8% respectively, p = 0.08; uncorrected: 14.6% vs 27.6% and 28.1% respectively, p = 0.005). In the intention to treat analysis, the rate of early treatment failure was high in all three groups (AS+AQ 13.3%; AL 15.2%; and AS+CD 9.3%, p = 0.2) primarily due to vomiting. However, the PCF28 corrected for re-infection was lower, though not significantly, in the AS+AQ group compared to the AL or the AS+CD groups (AS+AQ 18.3%; AL 24.2%; AS+CD 20.8%, p = 0.4) The incidence of adverse events was comparable between the groups. Conclusions AS+AQ is an appropriate first line treatment for uncomplicated malaria in Ghana and possibly in the neighbouring countries in West Africa. The effectiveness of AL in routine programme conditions needs to be studied further in West Africa. Trial Registration ClinicalTrials.gov NCT00119145
Patterns and seasonality of malaria transmission in the forest-savannah transitional zones of Ghana
Dominic B Dery, Charles Brown, Kwaku Asante, Mohammed Adams, David Dosoo, Seeba Amenga-Etego, Mike Wilson, Daniel Chandramohan, Brian Greenwood, Seth Owusu-Agyei
Malaria Journal , 2010, DOI: 10.1186/1475-2875-9-314
Abstract: A total of 23,406 mosquitoes were caught from 919 traps over the two-year period (November 2003 to November 2005): 54.3% were Culicines, 36.2% Anopheles funestus, and 9.4% Anopheles gambiae. Infection rates with Plasmodium falciparum were 4.7% and 1.5% for Anopheles gambiae and Anopheles funestus, respectively. Entomological inoculation rates (EIRs) were 269 infective bites per person per year in the first year (November 2003-October 2004) and 231 the following year (November 2004-November 2005). Polymerase Chain Reaction (PCR) analysis detected only Anopheles gambiae s.s. Nineteen mosquitoes were tested by PCR in the wet season; 16 were S-molecular form, 2 M-molecular form and 1 hybrid (S/M). In the dry season, sixteen mosquitoes were tested; 11 S-molecular form, 2 M-molecular form and 3 S/M hybrids. The frequency of knock down resistance (kdr) genotypes F(R) was 0.60.The dynamics and seasonal abundance of malaria vectors in the Kintampo area was influenced by micro-ecology, rainfall and temperature patterns. Transmission patterns did not differ significantly between the two years (2004 and 2005) and both Anopheles gambiae and Anopheles funestus were identified as effective vectors. EIR estimates in 2004/2005 were between 231 and 269 infective bites per person per year. The information provided by the study will help in planning intensified malaria control activities as well as evaluating the impact of malaria interventions in the middle belt of Ghana.Malaria remains a major public health threat in sub-Saharan Africa as the most efficient vector, Anopheles gambiae s.l, continues to adapt to humans [1] and is a complex of sibling species taxa, thus resulting in a high vectorial capacity. The complex consists of seven species that vary in their ability to transmit malaria [2]. Currently known sibling species within the complex include An. gambiae s.s. Anopheles arabiensis, Anopheles melas, Anopheles merus, Anopheles quadrianulantus (A and B) and Anopheles bwambae. Th
Family Planning Awareness, Perceptions and Practice among Community Members in the Kintampo Districts of Ghana  [PDF]
Obed Ernest A. Nettey, Yeetey A. Enuameh, Emmanuel Mahama, Abubakari Sulemana, George Adjei, Stephaney Gyaase, Samuel Afari-Asiedu, Robert Adda, Abena Konadu Yawson, Gifty Fosuaa Nuamah, Edward Apraku Anane, Livesy Abokyi, Charles Zandoh, Martha Abdulai, Ellen Abrafi Boamah, Kwame Adjei, Seeba Amenga-Etego, Francis Dzabeng, Charlotte Tawiah-Agyeman, Frank Baiden, Kwaku Poku Asante, Seth Owusu-Agyei
Advances in Reproductive Sciences (ARSci) , 2015, DOI: 10.4236/arsci.2015.31001
Abstract: Family planning is known to prevent maternal deaths, but some social norms, limited supplies and inconsistent use makes this difficult to achieve in most low- and middle-income countries. In spite of the high fertility levels in most sub-Saharan African countries and the potential economic benefits of family planning, its patronage remains very low in the sub-region. This study was with the objective of identifying the levels of awareness, utilization, access to and perceptions about family planning and contraception. A cross-sectional study design was used for the study, with data collected from multiple sources using both quantitative and qualitative approaches. Relevant findings included a marked disconnect between family planning/contraceptive knowledge and use. The pills and injectables were the most frequently used, but females in the study population poorly patronised emergency contraception. Supplies of most family planning methods were found to be health facility based, requiring clients to have to necessarily go there for services. Some respondents harboured perceptions that family planning was the responsibility of females alone and that it fuelled promiscuity among female users. Recommendations made include ensuring that health facilities had adequate staff and expertise to provide facility-based family planning services and also to disabuse the minds of community members of the negative perceptions towards family planning.
Accuracy of Rapid Tests for Malaria and Treatment Outcomes for Malaria and Non-Malaria Cases among Under-Five Children in Rural Ghana
Frank Baiden, Jayne Webster, Mathilda Tivura, Rupert Delimini, Yvonne Berko, Seeba Amenga-Etego, Akua Agyeman-Budu, Akosua B. Karikari, Jane Bruce, Seth Owusu-Agyei, Daniel Chandramohan
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0034073
Abstract: Background WHO now recommends test-based management of malaria across all transmission settings. The accuracy of rapid diagnostic test (RDT) and the outcome of treatment based on the result of tests will influence acceptability of and adherence to the new guidelines. Method We conducted a study at the Kintampo hospital in rural Ghana to evaluate the performance of CareStart, a HRP-2 based RDT, using microscopy as reference. We applied IMCI treatment guidelines, restricted ACT to RDT-positive children and followed-up both RDT-positive (malaria) and RDT-negative (non-malaria) cases over 28 days. Results 436 children were enrolled in the RDT evaluation and 391 (children with haemoglobin >8.0 gm/dl) were followed-up to assess treatment outcomes. Mean age was 25.4 months (s.d. 14.6). Sensitivity and specificity of the RDT were 100.0% and 73.0% respectively. Over the follow-up period, 32 (18.5%) RDT-negative children converted to positive, with 7 (4.0%) of them presenting with fever. More children in the non-malaria group made unscheduled visits than children in the malaria group (13.3% versus 7.7%) On all scheduled follow-up visits, proportion of children having a temperature higher than that recorded on day 0 was higher in the non-malaria group compared to the malaria group. Reports of unfavourable treatment outcomes by caregivers were higher among the non-malaria group than the malaria group. Conclusions The RDT had good sensitivity and specificity. However a minority of children who will not receive ACT based on RDT results may develop clinical malaria within a short period in high transmission settings. This could undermine caregivers' and health workers' confidence in the new guidelines. Improving the quality of management of non-malarial febrile illnesses should be a priority in the era of test-based management of malaria. Trial Registration ClinicalTrials.gov NCT00832754
Haematological and Biochemical Reference Values for Healthy Adults in the Middle Belt of Ghana
David K. Dosoo, Kingsley Kayan, Dennis Adu-Gyasi, Evans Kwara, Josephine Ocran, Kingsley Osei-Kwakye, Emmanuel Mahama, Stephen Amenga-Etego, Philip Bilson, Kwaku P. Asante, Kwadwo A. Koram, Seth Owusu-Agyei
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0036308
Abstract: Background Reference values are very important in clinical management of patients, screening participants for enrolment into clinical trials and for monitoring the onset of adverse events during these trials. The aim of this was to establish gender-specific haematological and biochemical reference values for healthy adults in the central part of Ghana. Methods A total of 691 adults between 18 and 59 years resident in the Kintampo North Municipality and South District in the central part of Ghana were randomly selected using the Kintampo Health and Demographic Surveillance System and enrolled in this cross-sectional survey. Out of these, 625 adults made up of 316 males and 309 females were assessed by a clinician to be healthy. Median values and nonparametric 95% reference values for 16 haematology and 22 biochemistry parameters were determined for this population based on the Clinical Laboratory and Standards Institute guidelines. Values established in this study were compared with the Caucasian values being used currently by our laboratory as reference values and also with data from other African and western countries. Results Reference values established include: haemoglobin 113–164 g/L for males and 88–144 g/L for females; total white blood cell count 3.4–9.2×109/L; platelet count 88–352×109/L for males and 89–403×109/L for females; alanine aminotransferase 8–54 U/L for males and 6–51 U/L for females; creatinine 56–119 μmol/L for males and 53–106 μmol/L for females. Using the haematological reference values based on the package inserts would have screened out up to 53% of potential trial participants and up to 25% of the population using the biochemical parameters. Conclusion We have established a panel of locally relevant reference parameters for commonly used haematological and biochemical tests. This is important as it will help in the interpretation of laboratory results both for clinical management of patients and safety monitoring during a trial.
Page 1 /3838
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.